nausea

nausea

nausea, sensation of discomfort, or queasiness, in the stomach. It may be caused by irritation of the stomach by food or drugs, unpleasant odors, overeating, fright, or psychological stress. It is usually relieved by vomiting. Nausea is frequently present during the early months of pregnancy, and it is a concomitant of motion sickness. However, nausea may also be the symptom of a serious illness; thus persistent nausea should receive medical attention.

Discomfort in the pit of the stomach associated with disgust for food and a feeling that vomiting will follow, as it often does. Nausea results from irritation of nerve endings in the stomach or duodenum, which stimulate brain centres that control nausea and vomiting. Nausea can be a symptom of minor or serious disorders. Common causes include indigestion (from eating too fast or from stress around mealtime), food poisoning, motion sickness, and pregnancy (morning sickness). Nausea may also arise from any cause of abnormal lack of appetite (e.g., shock, pain, influenza, badly fitting dentures, liver or kidney disease). Simple nausea often is relieved by vomiting.

Causes

Nausea is also an adverse effect of many drugs, and may also be an effect of a large intake of sugary foods.

Nausea is not a sickness, but rather a symptom of several conditions, many of which are not related to the stomach. Nausea is often indicative of an underlying condition elsewhere in the body. Travel sickness, which is due to confusion between perceived movement and actual movement, is an example. The sense of equilibrium lies in the ear and works together with eyesight. When these two don't "agree" to what extent the body is actually moving the symptom is presented as nausea even though the stomach itself has nothing to do with the situation. The reason for the stomach's involvement is thought to be the brain concluding that one of the senses is hallucinating, and further conclude that this is due to poison ingestion. The brain then induces vomiting to clear the supposed toxin.

In medicine, nausea can be a problem during some chemotherapy regimens and following general anaesthesia. Nausea is also a common symptom of pregnancy, in which it is called "morning sickness." Mild nausea experienced during pregnancy can be normal, and should not be considered an immediate cause for alarm.

Treatment

While short-term nausea and vomiting are generally harmless, they may sometimes indicate a more serious condition, such as coeliac disease. When associated with prolonged vomiting, it may lead to dehydration and/or dangerous electrolyte imbalances.

Symptomatic treatment for nausea and vomiting may include short-term avoidance of solid food. This is usually easy as nausea is nearly always associated with loss of appetite. If the patient is dehydrated, rehydration with oral or intravenous electrolyte solutions may be required. If the cause of the nausea is motion sickness, then sitting down in a still environment may also help.

There are several types of antiemetics, and researchers continue to look for more effective treatments. The main types used post-operatively for surgical patients are ondansetron, dexamethasone, promethazine, diphenhydramine, and in small doses droperidol. Doxylamine is the drug of choice in pregnancy-related nausea. When ingested or inhaled, marijuana has been shown to reduce nausea in the majority of users. Also available are a variety of non-invasive, but often untested, mechanical devices for suppressing nausea due to motion sickness.

The spices ginger and peppermint have also been used for centuries as a folk remedy to treat nausea, and recent research has supported this use.